Looked in the 1967-72 AMC Parts Manual.
Group # 1.046-1
for V8's 1967-72 they only show one part number
# 448 7181
I have a '69 343 with 3 bolt main pulley that only has 2 grooves.
Could it be that a 3 bolt pulley with 3 grooves was not produced ?
Not until later, like post '72, were 3 groove pulleys used ?
And that's when the water pumps got 3/8 taller
but the water pump pulleys got deeper also.
When I tried a '72 & up taller water pump and deeper pulley
with the earlier 3 bolt main pulley, they did not line up
but that could have just been my luck, you may fair better.
Did you also get the water pump pulley from the same
junkyard motor that you got the 4 bolt main pulley from ?
To get a 3 groove main pulley it sounds like you're gonna need a 4 bolt dampener.
